Provide a way to refresh token for Auth Webhook

[hackerwins]

Description:

We have added the auth webhook feature in #188, which allows the Client to verify whether it has access rights to a specific Document. The current implementation only utilizes the initially provided token for authentication, and there is no functionality for token refresh once it expires.

(5) response the request  (4) handle the request
     ┌─────────────────┐  ┌──┐
     │                 │  │  │   (3) response
     ▼                 │  ▼  │    - allowed
 ┌──────┐             ┌┴─────┤    - reason   ┌──────────────┐
 │Client├────────────►│Server│◄──────────────┤Outside Server│
 └──────┘ (1)request  └────┬─┘               └──────────────┘
           - token         │                      ▲
           - dockey        └──────────────────────┘
                               (2) call webhook
                                - token
                                - dockey
                                - verb: r or rw

• https://yorkie.dev/docs/cli#auth-webhook

To enhance the user experience, I propose implementing a token refresh mechanism. This would involve two key components:

• A. Server: After calling the Auth Webhook, if the token has expired, it should notify the Client of the token expiration.
• B. Client: Upon receiving the expiration event from the Server, the Client should provide an interface that allows the injection of a refreshed token (similar to an auth callback).

Related to #188 (comment)
Related to yorkie-team/codepair#160

Why:

Implementing this token refresh mechanism will ensure that users can maintain their sessions without interruptions, thereby providing a seamless and continuous experience while working with the Client.

[krapie]

@xet-a Seems like this issue is somewhat similar to your previous refresh token work on CodePair?

[xet-a]

I'm interested in this issue. Can I try this?

[krapie]

@xet-a Assigned 😄